Liquid reconditioning, for repetitive recycling, has many applications. For example, many machining systems employ a flushing medium in the form of a liquid with the flushing medium being reconditioned and repetitively recycled. Dependent on the requirements of the particular system, the reconditioning can include one or several operations. Often, the removal of particulate material is one of the reconditioning operations with that operation being performed by one of many alternative filtering media.
One problem encountered in nearly every filtering operation is blinding of the filter medium by accumulated particulate material. This results in an increase in pressure drop with an attending decrease in flow through the filter. In many applications, this condition requires a replacement of the filter medium, either by shutting down the system or by switching to a back-up filter. The former necessarily requires personal attention and often results in a disruption of the primary purpose of the system, machining a work piece, for example. The latter, while allowing the system to continue in operation, requires a duplication of system elements which increases the expense of the system.
Diatomite filter media, and their regeneration, are known to the prior art. Such filters employ diatomite which is formed as a layer on a supporting septum and which have proven highly efficient in the removal of particulate materials. As with all filters, continuing operation results in blinding. However, a diatomite filter may be regenerated by repositioning the diatomite on the septum as by mechanically displacing the diatomite and allowing it to reform on the septum. Such regeneration may be accomplished several times before it is necessary to replace the diatomite material. Thus, the utility of a back-up system is greatly reduced. However, those diatomite systems known to the inventor of the present invention require that the regeneration be accomplished manually which requires the same personal attention as is necessary during filter media replacement.